Biff the Cat Comes Through the Catflap

The description from YouTube:

This is typical. It beats me how human civilisation ever advanced when they can’t even sort out a reasonably-sized catflap for me. As if trying to squeeze through that hopelessly miniscule hole isn’t humiliating enough, they have to leave carrier bags full of bottles for recycling by the entrance, which makes the whole pallaver noisy and tiresome. I wouldn’t mind but the Master and Mistress frequently stand there and guffaw as I struggle to get into the house. I can’t see the joke myself, but I’ve learned that humans are strange, mysterious creatures.